Postitive pressure pump



Aug. 21, 1962 H. D. LowRY POSITIVE PRESSURE PUMP Filed 001'.. 28, 1960INVENTOR.

Heey/QN DALE Lon/ey 3,050,009 POSITIVE PRESSURE PUMP Herman Dale Lowry,Los Angeles, Calif., assignor to Lowry Hydraulic Co., Santa Monica,Calif., a corporation of Nevada t Filed Oct. 28, 1960, Ser. No. 65,699 3Claims. (Cl. 10S-125) The present invention relates generally to uidpumps and more particularly is ldirected to a positive pressure pumphaving unusually high fluid pumping capacity for its size and weight.

In general the preferred embodiment of the invention hereinafterillustrated and described in detail contemplates the provision of ahollow housing or casing within which are formed a central cavity and anumber of `outer cavities arranged in symmetrical rela-tion yabout thecentral cavity. The cavities are deiined by generally cylindrical walls,and each of the outer cavities overlaps the inner cavity whereby theinner cavity is in fluid communication with each of the youter cavitiesthrough openings constituting interruptions in the cylindrical sidewal-ls. An impeller member or rotor is rotatably mounted within thecentral cavity. The rotor proper is of somewhat smaller radius than -theradius of the central cavity and the periphery of the rotor is providedwith a number of equally arcuately spaced ribs extending longitudinallyof the rotor and projecting outwardly into sliding, virtually Huid-tightcontact with the central cavity wall. In each of the outer cavitiesthere is rotatably mounted `an idler wheel having a generallycylindrical outer surface in sliding, virtually uid-tight contact withthe cylindrical side wall defining its cavity, the outer surface rof theidler wheel being interrupted by a plurality of equally arcuately spacedlongitudinally extending grooves. The spacing of the longitudinal ribsor ridges of the rotor and the grooves of the idler wheels, as well astheir respective sizes and shapes, permits the ridges to be received inthe grooves during rotation of the rotor, thereby rotatably driving theWheels. The contact of the ridges with the grooves, supplemented bycontact between the peripheries of the rotor and the idler wheels, makesa continuous virtually fluid-tight seal during rotation and the endsurfaces of the rotor `and wheels are -similarly in virtually huid-tightcontact with the internal Walls of the housing. 'Ihe constructionincludes passageways or channels whereby to feed incoming fluid to bepumped to corresponding sides of the idler wheels near their juncturewith the rotor and similar output passageways or channels are providedon .the opposite sides of the rolling junctures between the rotor andwheels. Rotation of the rotor by an external source of power causespumping of fluid through the channels just mentioned in somewhat thesame way as the operation of a conventional gear pump.

A particular advantage of the present invention is its adaptability forextreme light-weight construction while maintaining Ia volumetriceicieney approaching 0 percent. This is accomplished by the use ofinterference tts between the various moving parts and between the movingparts and the stationary portions of the housing, the parts in abuttingsliding contact being made of a material having some yielding orresilient characteristics such as Teon, nylon or the like. Thisconstruction virtually eliminates Huid slippage and cavitation and thepump as a result has unusually advantageous. suction characteristics inuse. The ridges carried by the rotor g Patented Aug. 2l, 1952 may beintegrally formed with the rotor or, Ias ywill be described hereinafter,may desirably take the form of rollers received in 'grooves formed inthe rotor periphery, the'outer ends of the rollers being received inguide channels formed in the housing of the pump. Such constructionpermits the rollers to distribute ythe wear on their surfaces andyfurthermore yfacilitates easy removal `and replacement of the rollerswhen desired. Thus, the eiiiciencygof the pump can be maintained at avery high level. The resilient or the yielding characteristics of theseveral components ofthe pump permit handling of tluid having somesolids therein, and the presence of such Small solids does not harm thepump structure. For this reason the pump is particularly well adapted tothe pumping of oil and similar fluids where some solid particles may berentrained in Ithe fluid. The rollers themselves may be hollow ortubular in form in order to additionally permit some yielding whennecessary during operation.

Accordingly, it is a principal object of the present invention toprovide a novel pump of high etliciency and capacity for its volume andWeight. Additional objects and pur-poses of the invention are todisclose of the 4above characteristics wherein ya central rotor providedwith outwardly projecting ridges is elfectively in mesh with a pluralityof idler wheels having grooves for receiving the ridges therein, thewheels being in huid-tight contact with the rotor and with the xedportions of the housing of the pump; to disclose such a constructionwherein major components are made of a material having -at leastslightly yield-ing characteristics in order to permit .a negativ-e orinterference lit between the parts; to provide such a pump cap-able ofhandling small solid particles in the huid pump without substantial harmto the pump itself; and for other objects and purposes as will becomeclear from a reading of the following description of a preferredembodiment of the invention taken in connection with the accompanyingdrawing in which:

FIG. 1 is a'side elevational view of a pump embodying the presentinvention.

FIG. 2 is an end View thereof.

FIG. 3 is a sectional View of the pump taken on line III-Ill of FIG. 4.

FIG. 4 is a sectional View taken on line IV-IV of FIG. 3.

FIG. 5 is a fragmentary view of the central portion of FIG. 4 showing amodied construction of the rollers carried by the rotor.

Referring now in detail to the drawings, a pump embodying the 'presentinvention is indicated generally at 10 in FIG. 1 and includes a centralcore section indicated generally at 12 sandwiched between left and rightend members indicated generally at 14 and 16, respectively. The partsare held in assembled relation by suitable means such as through bolts18 and the central core is provided with openings constituting inlet andoutlet ports Z0 and 2,2, respectively. As will be seen in FIG. 2, theinlet and outlet ports may be connected to suitable conduits or pipes 24and 26, respectively, for connection to uid lines as desired.

Reference to FIGS. 3 and 4 will show the internal construction of thecore member 12. A number of cavities are formed within the coreincluding a central cavity indicated general-ly at 30 and a number ofouter cavities indicated generally at 32, 34 and 36, the outer cavitiesbeing equally spaced arcuately .about the center of the central cavity3l). Each of the outer cavities is of such a size and so locatedrelative to the central cavity Sil that the central cavity overlaps eachof the three outer cavities so that the cavities are in luidcommunication `with one another through openings constitutinginterruptions in the cylindrical side walls of the several cavities.

Rotatably mounted within the central cavity an impeller member or rotorindicated generally at 38 land having a generally cylindrical penipheryitl at a substantially smaller radius from the center of the pump thanthe cylindrical wall 4Z delining the cavity 3S. Means are providedforming in eiect longitudinally extending ribs equally arcuately spacedabout the periphery of the rotor 38 and projecting outwardly intosliding contact with'the inner wall 42 of the central cavity. In thepresent illustrative embodiment of the invention such longitudinal ribsare formed by a number of rollers 44, each roller being received lin alongitudinally extending groove i6 formed in the periphery of the rotor38 and extending throughout the length of the rotor. Desirably, ltherollers t 44 extend beyond the ends of the rotor 33, and end portions 48and Si) of the rollers are received in annularv grooves 52 and 54,respectively, formed in roller guides S6- and 58. The latter members areseated in suitably formed recesses in the inner surfaces of the endmembers 14 and 16, respectively. Seal means are desirably providedbetween the roller gu-ides 56 and 58 and the central core 12 such sealsbeing here indicated at di)y and 62, respectively, and desirably beingmade of Teilon or a similar smooth-surfaced, preferably somewhatcompressible material.

With further reference to FIG. 4, idler wheels indicated generally at66, 68 and 70 are rotatably received within the cavities 32, 34 and 36,respectively. The idler wheels have ya generally cylindrical peripheryinterrupted by a plurality of equally arcuately spaced longitudinallyextending grooves 72. These grooves are so shaped as to partiallyreceive rollers d4 during rotation of the rotor 38, as will beunderstood from a consideration of the dierent positions of the variousparts as seen in FIG. 4. Rotor 3S is provided with a central bore 76 andis mounted upon a central shaft indicated generally -at 78 and is keyedthereto at 80. Shaft 78 is carried by bearings S2 mounted Within the endmembers 14 and 16 and the shaft projects rightwardly as seen in FIG. 3outwardly of the pump passing through a suitable sealing means 84 to beconnected to a suitable source of rotational power for operation of thepump. Under some circumstances, a thrust load may be present and in thepresent embodiment of the invention such a load may be borne by thethrust bearing 86 mounted in the end member i4 and abutting an enlargedportion 88 of shaft 78. The idler wheels 66, 68 and 70 may be centrallybored `and Vmounted upon shafts 90, although this is not alwaysnecessary since kthe outer cavities within which the idler wheels rotateextend cylindrically well over one-half a circle and therefore the idlerwheels can float Within their respective cavities. As will be seen inFIG. 3, support shafts 96,

. i Y ways are formed in the core 12 and lie generally in parallelspaced planes perpendicular to the axis of the shaft 73. Thus, inletport 2i) is in communication with inlet passageway liiii, while outletport 22 is in communication with outlet passageway 162. 'Ihe latterVpassageway is in turn in communication with inwardly directed branchpassageways 164, 166 and 108, giving access to the meshing engagementofthe rotor 38 with idler wheels 32;, 34 and 36, respectively.Similarly, the inlet passageway d is in communication through branchpassageways 110, 112 and lll with the opposite sides of the idler wheels52, 34 and 36,' respectively. The two arcuate passageways 160 and .1.92need not extend completely around the pump, although they m-ay he formedin complete annuli if desired. The rollers 44 carried by the rotor 3Smay be made of metal or similar material, although by preference theyare made of Teilen or equivalent material having some com-pressibilityand desirably also self-lubricating qualities. It will be understoodthatthe rollers 44 together with the rotor 38 and any of the idlerWheels form a continuous Huid-tight connection during meshing movementof the parts in operation. For some uses it may be desirable to providegreater yielding qualities in the when used, may have their end portions92- received in bores formed in the end members 14 and 16, respectively,the end portions passing through openings formed in a pair of fixedseals 94 carried by the inner faces of the end members as shown. Seals94 are desirably made of a material such as Teflon and itis to beparticularly noted that seals 94 remain stationary during operation ofthe pump, while seals and 62.I necessarily rotate about the axis ofshaft 78 during operation.

Central coreY 12 is provided with conduit or pass-agev way means forleading fluid to` and away from the mesh- `ing' engagement of the rotor-38v and its rollers-44. with the several idler wheels. In FIG. 4 it isassumed that shaft 78 and therefore rotor 38 are rotatingcounterclockwisethrough the port 22. A pair of generally arcuatepassage-V rollers and for such purpose the construction of FIG. 5 may beused. In accordance with this form of the invention the rollers 144carried on the rotor 38 are of Teflon or equivalent material and arecentrally bored at 146 throughout their length. This permits evengreater yielding compressibility by the rollers and accordingly permitsthepump to handle lluid containing some solid particles without damageto the pump as the particles pass through.

Modifications and changes from the specilic forms of the inventionherein shown as illustrative will occur to those skilled in the art andall such modilcations and changes not departing from the spirit of theinvention are intended to be embraced within the scope of the appendedclaims.

I claimt 1.Y A positive pressure pump comprising:

a housing having formed therein iirst and second partially overlappingcavities having cylindrical side 'walls interrupted toform an openingcommunicating between the cavities;

a rotor rotatably mounted in the first cavity provided with longitudinalgrooves equally spaced about its periphery;

cylindrical rollers partially received in said grooves and ininterference lit Contact with the first cavity side wall;

means within the housing for retaining therollers in said grooves duringrotation of the rotor;

va Wheel rotatably mounted in the second cavity and having a cylindricalperiphery in interference fit con- Ytact withthe second cavity sideWall, said cylindrical Vperiphery being interrupted by a Vseries ofequally arcuately spaced longitudinal grooves arranged to successivelyreceive and mesh with the outer portions of said rollers in said openingin fluid-tight contact during rotation of the rotor and wheel, saidWheel periphery and rotor periphery being in interference tit Contactand said wheel and rotor being made of resilient material; V

inlet and outlet conduit means in the housing communicating withopposite sides Yor the meshing contact between the rollers and the Wheelgrooves in said opening;

and means for rotating said rotor.

wherein said (References on following page) Referenees Cited in the fileof this patent UNITED STATES PATENTS Chapman Mar. 25, 1873 Chapman Mar.25, 1873 Chapman Mar. 25, 1873 Phinney et a1 Apr. 22, 1879 Thomas Oct.24, 1950 Devlin Sept. 11, 1951 Maisch Nov. 25, 1952 6 English Nov. 3,1953 Quintilian Mar. 23, 1954 Quintilian Mar. 23, 1954 Hedman June 22,1954 Lindquist Dec. 21, 1954 Selden Jan. 1, 1957 Cook et al Jan. 8, 1957Mori Apr. 30, 1957 Butler Mar. 10, 1959

